Rotary speed indicator



E. J. WILSON. ROTARY SPEED INDICATOR. APPLICATION HLED'MAY29.19|7.

Patented May 16,1922.

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IE. .I WILSON. ROTARY SPEED INDICATOR. APPLICATION FILED MAY 29, I917.

I Patented May16, 1922.

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in VI 3% Q B aw \\w fix fi MAN 2 4 2 E a E. 1. WILSON.

ROTARY SPEED INDICATOR. APPLICATION FILED MAY 29. 1911.

1,416,083. Patented May16,1922.

3 SHEETS-SHEET 3.

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20 L RD I m j j d a a z 0 24 1 f g 4 If a I 6' a, %f B Z2 60 T A (\?& 7 m 3 F'zqzJJ. R, 2 9 5 f g Z a I g rmwnto'c 'l'znelyrl 176a on/ v attouwq EMERY J. WILSON-,- or CLEVELAND; oHro.

noranv srrlnn innroaron;

i nieces.

. Application filed ma 29,

indicated by the action of'centrifu'gal'force of a liquid contained in a rotatable receptacle and itconsists of a new device of new 7 form and construction to which may be j-applied exact mathematical formulae based'on the'laws of'centrifugal force of liquids. The invention further embodies features which enable the vital proportions of the construction on which such calculations are based to be attained with exactness and ease, so that, in manufacturing, all instruments are 'cor-' rectly and continuously calibrated throughout their entire range ofsp'eed. The present invention is a carrying forward of the general principles presented in my companion application filed December 21, 1916, Serial No. 138212. The basis of the principles presented in the'earlier' application is found in the fact that While a liquid mass subjected to centrifugal action naturally produces shifting of the vertex of the pa'-' rabola through distances Which are not proportional to the speed of rotation, it is possible to setup conditions wherein this shift of the vertex of the parabola takes place through distances which are proportional to the speed of rotation of the liquid mass, this result [being brought about by setting up forced positions of liquid mass equilibrium in place of. the natural positions of mass equilibrium. Such forced positions of equilibrium can be produced by employing a compensating face as a Wall of the chamber within which one of the free liquid surfaces of the'liquid mass travels during the mass displacing action set up by the changes in speed of rotation, such face being. traversed by the free liquid surface during travel of i the surface.

The compensating face has a cross sec tional contour of mathematically derived characteristic, the contour line being preferably produced bythe use of certain formulm which are used in developing: the contour line of the face. The general formulae underlying the'type of apparatus of which the earlier application 1sa disclosure of one e1nand its ease ofmanufacture.

Serial n. 171,725.

Specification of Letters-Pateiit.- Pat-myr m, & 922

bodinieiit are set forth in detailin thesaid earlier application; and are thereforenot re- 1 i peated'herein'. The particular embodiment of the earlier application, however, has this compensating face located as a; Wall of the inner chamber of theinstrument the chamber through Which the axis of rotationex tendsso that Where this surface is located ata'qifferent point, certain ofthe formulae employedare variedln order to meet the changed conditions.

provided In the present'invention this compensat outer or discharge chamber in constant liquid communication withthe inner orfixed central chamber about which the receptacle rotates, and indicating; means for registering.

thei change o flevel of the liquid in the central chamber due to centrifugalaction. A

leading feature of the invention is the-novel form of discharge chamber used to effect a desired relation betweenthe speed 'ofrotation aDClSfilCl change of level of the liquid in the central tube.

liquid surface in the axial chamber descends through distances which are not proportional to the speed of rotation, necessitating the use'either of a nouuniformlygraduated scale or .of various devices in the register operating mechanism such as cams. variable pitch spi.rals,etc.,to rectithe scale. This present invention provides anaexact mathecmatical. dcrlvationof the shape of the-(i153 In instruments of this type, prior. to said earlier invention.v the features o theinventioi'i relate to detailsof 7' construction which. have been found essential to the effic ent operation of the device My preferred form of construction com prises a fixedaxial chamber receptacle] sages connecting the two said chambers; a scale member having a cylindrical graduated surface adapted to be rotated about the axis of the receptacle by means of a float supported upon a mercury column contained in the axial chamber, said float having both an axial movement controlled by the rise and fall of said mercury due to centrifugal action of the mercury, and a movement of rotation controlled by a helical groove formed in said fixed axial chamber; the rotary. motion of the float being communicated to the scale member by means of a square spindle along which the float is free to slide.

A specific embodiment of my invention is illustrated in the accompanying drawings in which Figs. 1, 2 and 3 are front andside elevations and plan respectively of the device assembled; Figs. 1, 5, 6 and 7 are sections on the lines X-X, a-a, b-Z) and 0-0,

respectively, of Fig. 8; Fig. 9is an enlarged view of the outline of the discharge chamber showing the generating curve for the calibration surface; Figs. 10, 11 and 12 show developed diagrammatic views ofthe helix and the scale respectively to illustrate certain features in the operation of the device at low speeds; Fig. 13 is a diagrammatic view showing, in detail, the movement of the vortexes and the confining surfaces traversed by them, and Figs. le'and 15 are diagrammatic views used in deriving the mathematical formulae.

In the figures 1 indicates a face plate supporting the frame 2 which in turn supports the rotating unit comprising a body 3 and cap 1. A tubular member 5, held fixed at its upper end in the frame 2 by nuts 6 and 7, serves as a journal for the cap bearing 8 and extends downward into the body of the receptacle thereby forming a fixed axial chamher 9 about which the entire receptacle is free to rotate. The lower end of said tube 5 is provided with a plug 10 which has passages 11 uniting the chamber?) with the clearance space 12 surrounding the lower part of the tube; A discharge chamber 13 is formed between the body 3 and cap 4, and inclined passages 14; join the chamber 18 and clearance space 12 so that there is a constant liquid communication between the axial chamber 9 and the discharge chamber 13. The lower end of the body 3 is provided with an extension forming a step bearing 15, a journal 16, and carries a cross pin 17 at its lower end for rotating the receptacle as, for example, by means of aflexible'shaft (not shown). A bearing 18, supported by frame 2, receives the journal 16 and is provided with a screw thread 19 for attaching the flexible shaft coupling customarily used in automobile practice. Another screw thread 20 carried by the body 3 serves as a worm for driving the distance recording number wheels 21 shown enclosed in a suitable casing 22. Since this mechanism is of common use and does not concern this invention, except as it may enter the combination, further detail and description are not deemed necessary. The dial 23 is supported upon and rotated by the spindle 24: having an upper journal 25 in plug 26 which fits tight in the tube 5 and a pivot bearing 27 in plug 10 at the lower end of the tube. The spindle 24 is of square section and carries the float 28 which is free to slide along but not to rotate upon the spindle, said float being provided with a pin 29 which works in a spiral groove 30 formed in the fixed tube 5, so that as the float moves up and down along the spindle, the float, spindle and dial are all rotated by the pin following the groove. The dial 23 is graduated upon its outer cylindrical surface and the numbers 31 on the dial indicate miles per hour as is customary in automobile practice. The face plate 1 has .an opening through which a portion of the dial protrudes thereby exposing to view in the front elevation enough of the graduations and numbers to be easily read as the scale moves under the fixed index point 32.

In reducing this invention to practice certain details of construction have been found very essential to its eliicient andaccurate operation :There must be no liquid communication between the central chamber 9 andthe clearance space 12 except at a point 33 located centrally at the lower end of the tube 5, because the height of a liquid in the central chamber is calculated at the apex of the continued parabolic surface of the liquid in the discharge chamber as indicated in Fig. '9. If the outle 33 were located off center the height of liquid in the central chamher would be at a level above the said apex,

this level being determined by the point at which a vertical line through the outlet would intersect the said parabolic curve. It is to be noted that since the liquid in the central chamber does not rotate, its top free surface always remains a plane surface neglect-- ing of course the effect of capillurity. For this reason the passages 11 are shown inclined, and a tubular casing 34: is provided which fits snugly around the fixed tube and covers up the helical groove which is cut clear through the wall of the tube 5. A circular groove 35 of considerable depth is provided in the top surface of the body 3, which surface forms the bottom surface of the discharge chamber. This groove serves as a recess connecting the upper ends of the inclined passages 14 below the level X-X of the mercury when the instrument is at rest, and enables the mercury to rise and fall uniformly around the entire periphery 36 of the discharge chamber when the instrument is revolving at slow speeds. The introduction of a partition 37, held fast in the clear ance space 19. at the lower end of tube 5, and

another partition 38, shown in Fig. 4, in the discharge chamber 13, serves to enforce and sustain the rotationo-fthemercury in con formity with the receptacle, and makes the device more positive in action. The lower part of the float 28' is reduced iirdiameter and made slightly conical producii'ig aledge 39 to which the float normally sinks in the mercury due to its own weight, and permitting the float to settle easilyto this predeter mined level. I find that if the float is made the same diameter all the way down itdoes not tend to sinkto the same pointunder all workingv conditions, particularly so ifthere is a small clearance space between it and the tube 5. The top end of, the fioat is made conical to prevent drops ofmercury. remaining upon it when, for'example, the instrument is restored to its upright position'after having been inverted. j

The operation of the device is as follows :--l/Vhen the receptacle is not rotating the axial chamber 9,clearance space12, in-

clined passages 14 and-circular groove 35 are filled with mercury to the level X-,-X; the float 28 is raised to its highest or initial position as shown in Fig. 8, and the Zero on the scale is opposite the index point 32 as shown in Fig. 1. When the receptacle is rotated at a given speed the mercury descends a certain distanceH in the central chamber 9, thereby permitting the float to fall to the position 28 and at the same. timeto; be rotated through a certain angle by the pin moving in the groove 30. This rotation, is communicated to the dial 23 and the amount of rotation is indicated on the scale opposite the index pointBQ, The mercury flows from chamber 9 into. thej discharge chamber 13 where its free surface assumesa new position of equilibrium as shown at 40, due to the combined action of centrifugal force and gravity. The laws governing, this action are known and definite, and it is possible to determine from them the exact form of a calibrating surface {11, in. this discharge chamber which will cause the central mercury column to drop through it distances which are directly proportional to the speed of rotation. In Fig. 9 two positions of equilibrium P5 and P are shown corresponding to a small change in the speed. and the given assumed values of HzH and HzH Since the volume of mercury flowing from the central chamber'mustequal the volume which enters the discharge chamber we have (H -H times the net area of central chamberzthe volume bounded by the four surfaces P P the base line XX, and the calibration surface 41.

By applying the theory of limits to the above equation an exact equation for the generating curve of this calibration surface has been derived, giving the variable relation between the coordinates on andy of the curve. The equation shows that this calibration curveis tangent to the base line X X at a point which is at an infinite distance from the axis of rotation Y'Y. Hence a uniformly, graduated scale will not give the correct reading belowa certain speed of rotation depending on the maximum radius R of the calibration surface which itfis practical to use, unless the upper end of the helical groove is. changed to .a spiral groove of variable pitclr Referringto Figs. 10,11 and 12, the straight line 71.@ represents the upper end of the developed helical groove, the distancesh 72, 7L3 drawn to an enlarged scale, represent. the drops of the central mercury column for equal increments of"speed corresponding to 1 mile per hour scale division, these distances being variable down to a point M,.as the mercury works up along the vertical surface 36 in the discharge chamber. Beyond the point 1 M, the distances 7%, 72. h become uniform since the mercury is then working over the calibration surface 41 as previously ex-' plained. Fig. 12 shows how the scale would have to he graduated to give correct readings if acontinuous helical groove were used.

The broken line in Fig. 10 shows the developed spiral groove of variable pitch which is required a ove the point M to give a uniformly graduated scale as shown in Fig. 11, at these low speeds.

As shown by Figure 9, the compensating face 11 becomesactive in producing travel of the indicating freeliquid surface through equal distances for equal increments of speed, only after the instrument has reached a certain definite speed of rotation, the speeds below such minimum of thecoinpensating face range having their indications provided by the compensating means indicated diagrammatically.in Fig. 10. The manner of developing the compensating means of l 5. 10 has heretofore been pointed out.

For the purpose of making clear the development. of face 4-1, the followiilg explanation and for 1 mulze are given, this beingv based on thedisclosures found in Figures 13 to 15, these. formulze being more or .less a continuation of formulae shown in the said earlier application. p i p In Figure 13, the face 41 is indicated C, B indicatii'ig the opposing'surface of the outer chamber, this surface being of a selected geometrical design shown as pre sentingface which extends perpendicular to the axis of rotationof the instrument. As will beunderstood,ithe free liquid surfaceof the outerchamher traverses these two faces concurrently, these faces forming walls of fixed dimensions between which the liquid operating within the chamber is confined.

For purposes of illustration, two parabolic vortexes are, indicated, representing different positions of equilibrium of the liquid mass, the line 11 showing the vortex which represents the position of the free liquid surface at the time when the compensating face becomes active during the pro gressive increase in speed of rotation of the instrument; the line 11 showing the vortex produced when the speed of rotation is iiicreased to substantially the maximum of the instrument l/Vhen the instrument is at rest the free liquid surfaces of both chambers will extend on substantially the plane of surface B, this being represented by the line 10 During the travel of the vertex of the parabola from point i on the line n to the point the point where line al intersects the axis of rotationthe free liquid surface of the outer chamber is operating within the outer chamber under the principles of the natural law of centrifugal forces, the compensation for this range of travel of the vertex being provided by the spiral'groove formation. At

all points, however, in the travel of the ver tex of the parabola between the position 2' and the position 1 in Fig. 13, the compensating face C is active and the conditions of forced positions of mass equilibrium are set up.

The general operation, referring to Fig. 13, is as follows:

(1) As the speed increases from 11:0 to 11:11 :-The upper limit of the vortex curve travels upward from n to M along the cylindrical surface, radius R of the discharge chamber; the lower limit of the vortex curve intersects the base surface B at Z and the indicating surface moves downward from i to 2' in the central tube. For this range of speed the indicating surface moves through distances which are directly proportional to the square of the speed of rotation.

(2) As the speed increases from viz a to 02:01 (maximum) :The upper limit of the vortex curve travels upward from a to M along the calibration surface C the lower limit of the vortex curve travels inward from Z to Z along the base surface B; and the indicating surface moves downward from 2' to 2' in the central tube. For this range of speed the indicating surface moves through distances which are directly proportional to the speed of rotation due to the functioning of the calibration surface.

The following table indicates which proportions are assumed or are known constants, the variables indicated depending uponthe speed of rotation and these constants:

CONSTANTS.

The lower confining wall B of the discharge chamber is a plane surface perpen dicular to the axis of rotation. The zero level of the liquid lies in this plane.

Given basic proportions.

Z=uniform movement of float for one B. P. M. change of speed. p -'-radius of net area of central column;

i. e., if I r=inside radius of tube 5. a '=cross-sectional area of spindle. a cross-sectional area of groove in tube.

Then

w a a R =maximum radius of discharge chamber.

Derived constants.

c .0000142 (source found in application Ser. No. 138,212.) n =speed (R. P. M.) at which uniform movement of float starts. .H =length of non-uniform movement of float.

simply intersects such surface at the distance R from the axis; the annular groove at the periphery of the discharge chamber and Which lies below the zero level of the mercury may be of any desired width provided its inner wall does not come within the value of R it is made narrow to reduce the volume of mercury required.

.'.:'l'ro1n 2 4 and 5 VARIABLES.

71:11. 'P. M. I H displacementoi fioat from baseline or zero level. 7 R=horizontal coordinate of calibration curve. c

wzvertical coordinate of calibration curve.

The following general formula; are used in plotting the calibration curvethe contour of compensating face t1 and*l:'or determining the position of the iloat at "all speeds:

For calibration curve.

Limit :n For initial speeds.

M 0 +4 t me cn Rf. The principles employedinderiving these formulae are as follows: i v

(1) For initiaZ speeda Referringto Fig.

- volume dV flowing into the discharge chamber "for a small change of speed (Zn, is

equal to the known mercuryvolume wp zdn which flows from the central tube, we have (ZV='mp Zdn. But cZV can be expressed in ter'msofthe 'known constants c and Z, the speed n withits increment dn, and the vari- "able coordinates Rand m with their increments-dR and do so that'as cZ n approaches zeroas its limit, the resulting equation gives the variable relation betweenR and 0a and fo-r the initial speeds,that portion of the shifting of the vertex represented by the distance H in Fig. l8is as follows where the conditions are such as areindicated in "the 14, since the volume of mercury in the disdia shown as Fi v I q Vabc=1rp H (1) Vabc: Va'alo'c Vad0ba= Vadoc (Vadeba Vbovb) 1rR -x%R (I-I +50 rea ents "12am enema +56 +R -H=2 H- i- 2 From the general equation of the parabolic vortex a I l-l=cn R l (3) We have 1- i I v H+x=cn R or w=cn R -H :(4 And I I r v I) H I Y I'I- -CifiRfiOl R w -i "(5) 2 2 .Zmcn R -1 f GT3 The specific derivation of the compensating face under conditions such as shown in Fig. is as follows:

The curves P and P represent the parabolic vertexes corresponding to the speeds n and (71/(Z7?/) respectively, where (M is a Very small change of speed.

dV=volume of mercury flowing out of discharge chamber for a decrease of speed :cZa. This volume is bounded by the parabolic surfaces P and P the base surface B, and the compensating or calibration surface C.

icp ldn voluine of mercury flowing into center chamber for decrease of speedzdn.

Then cZV=1r Zdn as (in approaches 0 as its limit. I

(R +(ZR) [Z(n (in) w] (1 1) 1(72 -dn) R 617, 0;) r lu Zp Zdn (I) From the general equation of the parabolic Vortex cR n =H We have c(R+dR) (ndn) =l(ndn)+wcRn Zn a0 (2) c(r+dr (ndn) =l(ndn) r. (3)

' I cr n =ln H (4) Substituting in (I) :0(R +dR)(n-dn) ;cR n g= 2p ZtZn (II) From 1) and 2) 0(R cZRfUtdo? 011 a Zdn Substituting in (II):

011 121 ZZp dn 2 5 At the limit this becomes :(dn 0) 01 3 201MB ZOZp IL i re l I As will be understood, it is possible through the use of the compensatmgmeans R (Ill) for the initial speeds and the compensating itace'for the speeds Within the range limits of the face, derived under the formulae above pointed out, to produce an indicator i of this general type in which the indications are substantially uniformly spaced; and 1t will also be understood that it is possible,

because of these facts, to manufacture indicaters under production conditions, since it is possible to produce the compensatin face by the use of dies etc, so that the product will be uniform.

From the above it will be UlNiGlStOfifl that l: have provided a speed indicator wherein.

a confined liquid mass is subjected. to centrifugal action. to produce characteristics of a vortex, wherein the carrier for the liquid niass'is formed to provide inner and outer chambers in permanent communication and with each chamber having a free liquid surface of the mass, the free surfaces being in permanent connectionthrough the body of the mass, and whereinithe indications are made responsive to the changes in position of the free liquid surface ofthe mass ofthe inner chamber, such indicatorhaving means operative to establish definite positions of equilibrium of the mass at definite/speeds of rotation inpresence ofmass increment flow producedby variationsin speed, said means includinga'face of such outer chamher positioned to bewtrc versed by 'the 'free liquid surface operating in such chamber, saidface having a cross sectional contour of mathcmatically deriv'ed characteristic such as to cause the volumetric displacement represented by theniovement of the free liquid surfaceof the .outer chamber in moving from one position of mass equilibrium to another to be equal for equal increments of speed. i i

LHaving described my invention '1 claim as new :j' v I 1. In a speed indicator, a rotatable liquid receptacle having an axial chamber, a dis charge.chamber, an annular groove in said discharge chamber, andone or more passages uniting'the axial chamber with the groove, said passages entering the grooveat-points below the normal level of the liquidwhen the instrument isatrest. i i

2. A .speedindicator having inner and outer communicating chambers for receiving liquid, the outer chamber constituting a dischargechamber into which the liquidflows upon rotation, said dischargechauiber having for its lower boundary a plane surface provided with a peripheralgroove communi eating with the outerportion of said discharge chamber and having its upper sur face so rel atedtothe'lower surface that both surfaces are traversed by the free liquid surface; the relationbetween thesurfaces of said chambers being suclrthat equal variations in speedthroughout a given range produce equal variations inl-iqui'd levehand indicating fmeans responsive to; the liquid level.

3. r speed indicator having inner and outercommunicatingchambersfor receiving liqui d, the outer chamber constituting a di s charge chamber iuto whichthe liquid flows upon rotation as it leaves the surface of the inner chamber, said discharge ehamber 'havsing for its lower boundary a plane surf-ace provided with aperip'he algroove communicating-with the outer portion of said discharge chamber and having an upper surface cooperating therewith, some of the sur faces of said (chambers being of assumed formand the remaining surface having a a form calculated with reference tothe form oftheassumed surfaces in such manner that equal variations in speed throughout a given range produce equal variations in liquid level, and indicating means responsive to said liquid level. i

4. A speed indicator having inner and outer communicating chambers for receiving liquid, the outer chamber constituting a discharge chamber into which the liquid flows upon rotation'asit leaves the surface of the inner chamber, said discharge chamber having'twosurfaces" traversed by the. liquid upon rotation someof the surfaces of said chambers being of assumed form and the remaining surface having atform calculated withreference'tothe form of the assumed surfaces in such manner that equal variations in speed throughout a given range produce equal variations in liquid level witlr in the inner'chainber and indicating means responsivetosaid liquid'level.

' 5. A speed indicating device provided with wall portions' forming inner and outer communicating chambers concentric to an axis of rotation and containing a liquid, the wall portions of the inner chamber being stationary, means'for p;roducingrotation of the wall. portions of the outer chamber and of the liquidtherein about said axis'thereby causing flow ofiliqmd to the outer chamber,

said inner and outer chambers'havingztheir respective .wall portions so shaped and re-I lated toeach other as to produce uniform variations of level ofgthe liquid in the inner chamber f'fo-r uniform variations in speed of rotation, and indicating means responsive to said liquidlevel '6. In speed indicators, wherein a confined liquid mass is subjected to centrifugal action to produce characteristics of a vortex, Wherein the carrier for the liquid mass formed toprovideinner and outer chambers inpermanent communication and with each chamher having a freeliquid surface of the mass, the free surfaces'being in permanent connectionthrough the body of the mass, and

wherein theindications are made responsive to the changes in position of the free liquid surfaceof the mass ofthe inner chamber, means operative to establish definite posi-o tionsiof equilibrium of the mass at-definite speeds of rotation in presence of mass incren ent flow produced by variations in speed,

said means (including, a face of such outer,"

chamber positionedto be traversed by the free liquid surface operating in suchchamher, said face having cross sectional contour of mathemz-itically derived characteristic such as to cause the volumetric displacement represented by the movement of the free liquid surface of the outer chamber in moving frofmone position of mass equilibrium to another to be equal for equal incrementsjof speed.

' 7, In speedrindicators, wherein a confined liquid mass is subjected. to centrifugal action to produce characteristics of vortex, wherein thecarrier for the liquid mass is formed to provide inner and outer chambers in permanent communication and with each chamber having a free liquid surface of the mass, the free surfaces being in permanent connection through the body of the mass, and wherein the indications are made responsive to the changes in position of the'free liquid surface of the mass of the inner chamber, means operative to establish definite positions of equilibrium of the mass at definite speeds of rotation in presence of mass increment flow produced by variations in speed, said means including a pair of faces constituting wall portions of the outer chamber positioned to be concurrently traversed by the free liquid surface operating in such chamber, one of said faces being of selected geometrical design, the other of such faces having a cross-sectionalcontour of mathematically-derived characteristic such as to cause the volumetric disglacement represented by the movement of the free liquid surface over both faces in moving from one position of mass equilibrium to another to be equal for equal increments of speed.

8. In speed indicators, wherein a confined liquid mass is subjected to centrifugal action to produce characteristics of a vortex, wherein the carrier for the liquid mass is formed to provide inner and outer chambers in permanent communication and with each chamber having a free liquid surface of the mass, the free surfacesbeing in permanent connection through the body of the mass, and wherein the indications are made responsive to the changes in position of the free liquid surface of the mass of the inner chamber, means operative to establish definite positions of equilibrium of the mass at definite speeds of rotation in presence of mass increment flow produced by variations in speed,

said'means including a pair of faces constituting wall portions of the outer chamber positioned to be concurrently traversed by the free liquid surface operating in such chamber, one of said faces being of selected geometrical design, a crosssection of the wall carrying such face presenting the face as extending substantially perpendicular to the axis of rotation,the other of such faces having a cross sectiona-l contour of mathe matically-derived characteristic such as to cause the volumetric displacement represented by the movement of the free liquid surface over both faces in moving from one position of mass equilibrium to another to be equal for equal increments of speed.

9. In speed indicators, wherein a confined liquid'mass is subjected to centrifugal'action to produce characterlstics of a vortex, wherein the carrler for the liquid mass is formed to provide inner and outer chambers in permanent communication and with each chamber having a free liquid surface of the mass, the free surfaces being in permanent connection through the body of the mass, and wherein the indications are made responsive to the changes in position of the free liquid surface of the mass of the inner chamber, meansoperative to establish definite positions of equilibrium of the mass at diiinite speeds of rotation in presence of mass increment flow produced by variations in speed, said means including a pair of faces constituting wall portions of the outer chamber postioned to be concurrently traversed by the free liquid surface operating in such chamber, one of said faces being of selected geometrical design, a cross-section of the wall carrying such face presenting the face as extending substantially perpendicular to the axis of rotation, the other of such faces having a cross-sectional contour of mathematically derived characteristic such as to cause the volumetric displacement represented by the movement of the free liquid surface over both faces in moving from one position of mass equilibrium to another to be equal'for equal increments ofspeed, the direction of extension of the derived face within the limits of such equal displacement movement of the free liquid surface being such as to generally increase the distance between the faces in the direction of approach to the axis of rotation.

,10. I11 speed indicators, wherein a confined liquid mass is subjected to centrifugal action to produce characteristics of a paraboloid in which the position of the vertex is variable in response to speed changes, and wherein the indications are responsive to the positionchanges of the vertex, a container for the liquid, said container being mounted to produce paraboloidal characteristics to the confined liquid, said container having communicating inner and outer chambers for the liquid, said chambers being formed and positioned to provide free liquid surfaces of the mass permanently connected by the body of the mass with the surfaces located respectively to operate within the two chambers and with the liquid surface of the inner chamber movable in correspondence with the vertex movement, said surfaces being variable in position through flow of the liquid responsive to speed changes, variation. in position of the surfaces being such as to place them in definite relation to the lines of the changed paraboloidal conformation produced by the change in speed, said. 0011- tainer including a derived face forming a wall of the outer chamber and active in com trolling the amount of the liquidincrement shifted in producing the surface variations, said face having a cross-sectional contour 1,4.16,ose

such-as to cause travel of the vertex 'ofpredetermined length in presence of a speed change increment of definite amount, the length of vertex travel for successive speed increments being of predetermined amounts for equal speed increments. I

11. In speed indicators,-Whereina confined liquid mass is subjected to centrifugal action to produce characteristics of a paraboloid in which the position of the vertex is variable in response to speed changes, and where in the indications are responsive to the position changes of the vertex, a container for the liquid, said container being mounted to produce paraboloidal characteristics to the confined liquid, said container having conr municating inner and outer chambers for the liquid, said'chambers being formed and positioned to provide free liquid surfaces of the mass permanently connected by the body of the mass with the liquid surfaces located re spectively to operate within the two chambers and with the surface of the inner chain ber movable in correspondence with the vertex movement, said surfaces being variable in position through flow of the liquid responsive to speed changes, variation in position of the surfaces being such as to place them in definite relation to the lines of the changed paraboloidal conformation produced by the change in speed, said container including a derived face forming a wall of the outer chamber and active in controlling the amount of the liquid increment shifted in producing the surface variations, said face having a cross-sectional contour such as to cause travel of the vertex of predetermined length in presence of a speed change increment of definite amount, the length of vertex travel for successive speed increments being of pre determined and equal amounts for equal speed increments within the limits of mass flow in which the free liquid surface traverses such derived face.

12. In speed indicators, wherein a liquid mass is subjected to centrifugal action to produce characteristics of a vortex, and wh rein the indications are made responsive to the rise and fall changes in position of a free liquid surface with the changes resulting from mass increment flow between two permanently-communicating chambers of the liquid carrier, indicating mechanism. mechanism for translating the rise and fall movements of such free surface into indicating-mechanism movement, means operative Within definite speed limits for producing mass flow of equal increment amounts for equal increments of speed within. such limits whereby free surface travel will be equal for equal speed increments Within such limits, and means operative to compensate for mass flow of unequal increment amounts for equal increments of speedwithout such speed limit range, such compensating means i being effective to translate unequal lengths of travel of the free surface produced by speedincre merits of equal amounts into indicating mechanism movement in which the length of indicating mechanism movement is equal foraequal increments of speed.

13. An indicator as in claim 12, characterized. in that the mass flow of unequal increment amount precedes that of equal increment amount in an ascending progression of speedincrements of equal amount, with the compensating means active solely below the minimum limits of the mass flow of equal increment amounts.

14;. In speed indicators, wherein a liquid mass is subjected to centrifugal action, and wherein the carrier for the mass is formed to provide a pair of spaced-apart free liquid surfaces of and in permanent connection through the body of the mass, indicating mechanism, adapted to indicate variations in speed, and means rendered operative by the rise and fall of one of such free surfaces for producing equal travel of the indicating mechanism for equal increments of speed, said means including mechanism for translating such rise and fall movements of the surface into movement of the indicating mechanism, means operative in the translating mechanism for compensating for unequal travel distances of such free surface for equal increments of speed during a portion of such rise and fall movement, and a carrier face operative to produce equal travel distances of such surface for equal increments of speed during the remainder of such rise and fall movement of the surface.

15. An indicator as in claim it characterized in that the free liquid surfaces are respectively operative in inner and outer chambers of the carrier, with the free surface which is active in the movement of the translating mechanism located and operative within the inner chamber and with the carrier face for producing the equal travel movement of such free surface formed as a wall of the outer chamber and positioned to be traversed by the free surface of the outer chamber.

such free surface through equal distances increments of speed by equal lengthscof for equal increments of speed within definite travel of the mechanism indicator.

speed limits, and means operative in the In testimony whereof I affix my signature translating mechanism for compensating for in presence of two witnesses as follows: rise and fall movements of the surface EMERY J. WILSON.

through unequal distances for equal incre- Witnesses: s ments of speed without such limits whereby M. M. WILsoN, the indicating mechanism will indicate equal 0. W. UPSON. 

